/ Thesaurus / U Synonyms of upper bound Find synonyms for: Noun1. upper bound, boundary, edge, boundusage: (mathematics) a number equal to or greater than any other number in a given setWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: immense Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language